[Bug tree-optimization/85063] Switch conversion in openacc routine introduces unsupported construct

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85063

--- Comment #1 from Tom de Vries <vries at gcc dot gnu.org> ---
Created attachment 43748
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43748&action=edit
Tentative patch

Currently doing:
- bootstrap & reg-test on x86_64, and
- build and libgomp reg-test on x86_64 with nvptx accelerator.